Cleaning out childhood items recently, Antonia Zaferiou came across some of her grade-school writing. “I do everything with music,” it read. “When I walk, I listen to the beat of my footfalls.”
Today, that music echoes through her research. Her research group is evaluating how generating a drum beat for each footfall and other sounds affect movement strategies. The music also hums through a sample video on her website in which a dancer sways and bends, dips and twists, the dancer’s body dotted with sensors, as all around her a droning sound rises and falls in pitch, controlled by motions.
Zaferiou, an assistant professor in Stevens’ Department of Biomedical Engineering, uses sound-based biofeedback to improve balance and mobility. Her work at the Musculoskeletal Control and Dynamics Lab examines how people balance during whole-body rotations ― as when we turn around corners in our homes or turn abruptly toward someone calling our name ― and how sound-based biofeedback can be used to improve balance during those movements.
“We’re seeking to improve and preserve mobility,” Zaferiou says, adding that fall mitigation is a significant part of that. “If we think about older-adult health, it has almost become assumed that older adults will fall, but it’s a really big issue in quality of life and mortality.”
Zaferiou’s research toward reducing fall risk will be furthered by two recent grants. A National Science Foundation CAREER Award in the amount of $822,200 centers on how machine learning and wearable technology can be used to identify balance and gait deficits in fall-prone older adults and deliver auditory feedback to improve balance while walking. A National Institutes of Health Interdisciplinary Rehabilitation Engineering Research Career Development Program grant in the amount of $125,000 is supporting Zaferiou’s clinical research training and her work to understand the role of rhythm in sound-based biofeedback.
Rehabilitation facilities often use a timed beat from a device like a metronome to help patients learn or re-learn a cyclical movement like walking in a straight line. But studies have also suggested that older adults and adults with Parkinson’s disease may improve even more if they sing or create their own rhythm, literally walking to the beat of their own drum. One question Zaferiou aims to answer is whether sonification ― conveying data from an individual’s movement through sound in real-time ― would function more like an external cue (e.g., a metronome) or an internal cue (e.g., a song in your head).
“If you’re working with a patient trying to do a cyclical movement like walking in a straight line, maybe that metronome is fine,” Zaferiou says. “But if that person has to turn ― and 50 percent of our walking steps are turns ― does a fixed external rhythm conflict with the task or impose on them to alter their preferred turn timing?”
The sonification studies are in early stages of lab-based research. In regard to developing sonified balance biofeedback, Zaferiou is currently examining the interplay between the sway of the body as it walks and the contact its feet have simultaneously with the ground, studying the center of mass positioning relative to the feet.
“We’re trying to put the context for balance and the dynamics of balance together,” she says. “We’re learning a lot every single week. It’s in early stages, but we’re making sure we build a system that’s going to really help people balance.”
Her current clinical research focus is with older adults, but the technology could apply across multiple populations, including people with Parkinson’s disease, multiple sclerosis or autism and sensory disorders. Future funding could be used to grow the lab group to pursue some of these clinical applications, pay human subject participants ― who often struggle with mobility issues and miss work to contribute to the research ― and support collaboration with sound designers.
In addition to the clinical research, the lab has two existing grants from Major League Baseball to study pitching and batting. “It’s interesting to have clinical focus and sports performance focus because often we use the same methods for both,” Zaferiou said. “In addition, sports biomechanics research provides an excellent test bed for model systems of movement. Athletes and dancers hone their movement skills over years and years of practice and become experts at turning. We end up gaining insight from these model or expert movement systems.”
Someday down the road, Zaferiou envisions scenarios where older people might walk into a community-center type of lab for a sonic tune-up, to practice their motor and balance skills and at home, use personalized wearable sonification technology that would alert them to concerning changes in their gait and balance on a day-to-day basis.
“They would know what their movements normally sound like, and if they wake up the next day and it sounded different, they would be aware of that change and equipped to address an issue in its early stages,” she says.
Although that is a long-term goal, today, the lab is opening the door to a host of discoveries.
“My Ph.D., undergraduate, and high school students will say ‘Check out this graph,’ and ‘Wow, no one has ever seen this before’ ― and in these phases of doing these experiments, it happens quite often,” Zaferiou says. “Then that little spark of ‘No one has seen this before,’ quickly turns to ‘How do we explain this to people, how do we share and use this discovery?’”